Extract polymorphic Type methods for class-name narrowing

src/Analyser/ExprHandler/InstanceofHandler.php

@@ -12,7 +12,6 @@
 use PHPStan\Analyser\ExprHandler;
 use PHPStan\Analyser\MutatingScope;
 use PHPStan\Analyser\NodeScopeResolver;
-use PHPStan\Analyser\Traverser\InstanceOfClassTypeTraverser;
 use PHPStan\DependencyInjection\AutowiredService;
 use PHPStan\Type\BooleanType;
 use PHPStan\Type\Constant\ConstantBooleanType;
@@ -21,7 +20,6 @@
 use PHPStan\Type\ObjectType;
 use PHPStan\Type\StaticType;
 use PHPStan\Type\Type;
-use PHPStan\Type\TypeTraverser;
 use PHPStan\Type\TypeUtils;
 use function array_merge;
 use function strtolower;
@@ -94,9 +92,9 @@ public function resolveType(MutatingScope $scope, Expr $expr): Type
 			}
 		} else {
 			$classType = $scope->getType($expr->class);
-			$traverser = new InstanceOfClassTypeTraverser();
-			$classType = TypeTraverser::map($classType, $traverser);
-			$uncertainty = $traverser->getUncertainty();
+			$result = $classType->toObjectTypeForInstanceofCheck();
+			$classType = $result->type;
+			$uncertainty = $result->uncertainty;
 		}
 
 		if ($classType->isSuperTypeOf(new MixedType())->yes()) {

src/Analyser/TypeSpecifier.php

@@ -165,24 +165,9 @@ public function specifyTypesInCondition(
 			}
 
 			$classType = $scope->getType($expr->class);
-			$uncertainty = false;
-			$type = TypeTraverser::map($classType, static function (Type $type, callable $traverse) use (&$uncertainty): Type {
-				if ($type instanceof UnionType || $type instanceof IntersectionType) {
-					return $traverse($type);
-				}
-				if ($type->getObjectClassNames() !== []) {
-					$uncertainty = true;
-					return $type;
-				}
-				if ($type instanceof GenericClassStringType) {
-					$uncertainty = true;
-					return $type->getGenericType();
-				}
-				if ($type instanceof ConstantStringType) {
-					return new ObjectType($type->getValue());
-				}
-				return new MixedType();
-			});
+			$result = $classType->toObjectTypeForInstanceofCheck();
+			$type = $result->type;
+			$uncertainty = $result->uncertainty;
 
 			if (!$type->isSuperTypeOf(new MixedType())->yes()) {
 				if ($context->true()) {

src/Reflection/InitializerExprTypeResolver.php

@@ -93,7 +93,6 @@
 use PHPStan\Type\TypeCombinator;
 use PHPStan\Type\TypehintHelper;
 use PHPStan\Type\TypeResult;
-use PHPStan\Type\TypeTraverser;
 use PHPStan\Type\TypeUtils;
 use PHPStan\Type\TypeWithClassName;
 use PHPStan\Type\UnionType;
@@ -2451,54 +2450,7 @@ public function getClassConstFetchTypeByReflection(Name|Expr $class, string $con
 		}
 
 		if (strtolower($constantName) === 'class') {
-			return TypeTraverser::map(
-				$constantClassType,
-				function (Type $type, callable $traverse): Type {
-					if ($type instanceof UnionType || $type instanceof IntersectionType) {
-						return $traverse($type);
-					}
-
-					if ($type instanceof NullType) {
-						return $type;
-					}
-
-					if ($type instanceof EnumCaseObjectType) {
-						return new IntersectionType([
-							new GenericClassStringType(new ObjectType($type->getClassName())),
-							new AccessoryLiteralStringType(),
-						]);
-					}
-
-					$objectClassNames = $type->getObjectClassNames();
-					if (count($objectClassNames) > 1) {
-						throw new ShouldNotHappenException();
-					}
-
-					if ($type instanceof TemplateType && $objectClassNames === []) {
-						return new IntersectionType([
-							new GenericClassStringType($type),
-							new AccessoryLiteralStringType(),
-						]);
-					} elseif ($objectClassNames !== [] && $this->getReflectionProvider()->hasClass($objectClassNames[0])) {
-						$reflection = $this->getReflectionProvider()->getClass($objectClassNames[0]);
-						if ($reflection->isFinalByKeyword()) {
-							return new ConstantStringType($reflection->getName(), true);
-						}
-
-						return new IntersectionType([
-							new GenericClassStringType($type),
-							new AccessoryLiteralStringType(),
-						]);
-					} elseif ($type->isObject()->yes()) {
-						return new IntersectionType([
-							new ClassStringType(),
-							new AccessoryLiteralStringType(),
-						]);
-					}
-
-					return new ErrorType();
-				},
-			);
+			return $constantClassType->toClassConstantType($this->getReflectionProvider());
 		}
 
 		if ($constantClassType->isClassString()->yes()) {
@@ -2699,33 +2651,7 @@ public function getBitwiseNotType(Expr $expr, callable $getTypeCallback): Type
 
 	public function getBitwiseNotTypeFromType(Type $exprType): Type
 	{
-		return TypeTraverser::map($exprType, static function (Type $type, callable $traverse): Type {
-			if ($type instanceof UnionType || $type instanceof IntersectionType) {
-				return $traverse($type);
-			}
-			if ($type instanceof ConstantStringType) {
-				return new ConstantStringType(~$type->getValue());
-			}
-			if ($type->isString()->yes()) {
-				$accessories = [];
-				if (!$type->isNonEmptyString()->yes()) {
-					return new StringType();
-				}
-
-				$accessories[] = new AccessoryNonEmptyStringType();
-				// it is not useful to apply numeric and literal strings here.
-				// numeric string isn't certainly kept numeric: 3v4l.org/JERDB
-
-				return new IntersectionType([new StringType(), ...$accessories]);
-			}
-			if ($type instanceof ConstantIntegerType || $type instanceof ConstantFloatType) {
-				return new ConstantIntegerType(~ (int) $type->getValue());
-			}
-			if ($type->isInteger()->yes() || $type->isFloat()->yes()) {
-				return new IntegerType();
-			}
-			return new ErrorType();
-		});
+		return $exprType->toBitwiseNotType();
 	}
 
 	private function resolveName(Name $name, ?ClassReflection $classReflection): string

src/Type/Accessory/AccessoryArrayListType.php

@@ -483,6 +483,11 @@ public function toNumber(): Type
 		return new ErrorType();
 	}
 
+	public function toBitwiseNotType(): Type
+	{
+		return new ErrorType();
+	}
+
 	public function toAbsoluteNumber(): Type
 	{
 		return new ErrorType();

src/Type/Accessory/AccessoryLiteralStringType.php

@@ -181,6 +181,11 @@ public function toNumber(): Type
 		return new ErrorType();
 	}
 
+	public function toBitwiseNotType(): Type
+	{
+		return new StringType();
+	}
+
 	public function toAbsoluteNumber(): Type
 	{
 		return new ErrorType();

src/Type/Accessory/AccessoryLowercaseStringType.php

@@ -178,6 +178,11 @@ public function toNumber(): Type
 		return new ErrorType();
 	}
 
+	public function toBitwiseNotType(): Type
+	{
+		return new StringType();
+	}
+
 	public function toAbsoluteNumber(): Type
 	{
 		return new ErrorType();

src/Type/Accessory/AccessoryNonEmptyStringType.php

@@ -183,6 +183,11 @@ public function toNumber(): Type
 		return new ErrorType();
 	}
 
+	public function toBitwiseNotType(): Type
+	{
+		return new IntersectionType([new StringType(), new self()]);
+	}
+
 	public function toAbsoluteNumber(): Type
 	{
 		return new ErrorType();

src/Type/Accessory/AccessoryNonFalsyStringType.php

@@ -185,6 +185,11 @@ public function toNumber(): Type
 		return new ErrorType();
 	}
 
+	public function toBitwiseNotType(): Type
+	{
+		return new IntersectionType([new StringType(), new AccessoryNonEmptyStringType()]);
+	}
+
 	public function toAbsoluteNumber(): Type
 	{
 		return new ErrorType();

src/Type/Accessory/AccessoryNumericStringType.php

@@ -177,6 +177,11 @@ public function toNumber(): Type
 		]);
 	}
 
+	public function toBitwiseNotType(): Type
+	{
+		return new IntersectionType([new StringType(), new AccessoryNonEmptyStringType()]);
+	}
+
 	public function toAbsoluteNumber(): Type
 	{
 		return $this->toNumber()->toAbsoluteNumber();

src/Type/Accessory/AccessoryUppercaseStringType.php

@@ -178,6 +178,11 @@ public function toNumber(): Type
 		return new ErrorType();
 	}
 
+	public function toBitwiseNotType(): Type
+	{
+		return new StringType();
+	}
+
 	public function toAbsoluteNumber(): Type
 	{
 		return new ErrorType();

src/Type/Accessory/HasOffsetType.php

@@ -427,6 +427,11 @@ public function toNumber(): Type
 		return new ErrorType();
 	}
 
+	public function toBitwiseNotType(): Type
+	{
+		return new ErrorType();
+	}
+
 	public function toAbsoluteNumber(): Type
 	{
 		return new ErrorType();

src/Type/Accessory/HasOffsetValueType.php

@@ -506,6 +506,11 @@ public function toNumber(): Type
 		return new ErrorType();
 	}
 
+	public function toBitwiseNotType(): Type
+	{
+		return new ErrorType();
+	}
+
 	public function toAbsoluteNumber(): Type
 	{
 		return new ErrorType();

src/Type/Accessory/NonEmptyArrayType.php

@@ -472,6 +472,11 @@ public function toNumber(): Type
 		return new ErrorType();
 	}
 
+	public function toBitwiseNotType(): Type
+	{
+		return new ErrorType();
+	}
+
 	public function toAbsoluteNumber(): Type
 	{
 		return new ErrorType();

src/Type/Accessory/OversizedArrayType.php

@@ -439,6 +439,11 @@ public function toNumber(): Type
 		return new ErrorType();
 	}
 
+	public function toBitwiseNotType(): Type
+	{
+		return new ErrorType();
+	}
+
 	public function toAbsoluteNumber(): Type
 	{
 		return new ErrorType();

src/Type/BooleanType.php

@@ -66,6 +66,11 @@ public function toNumber(): Type
 		return $this->toInteger();
 	}
 
+	public function toBitwiseNotType(): Type
+	{
+		return new ErrorType();
+	}
+
 	public function toAbsoluteNumber(): Type
 	{
 		return $this->toNumber()->toAbsoluteNumber();

src/Type/CallableType.php

@@ -409,6 +409,11 @@ public function toNumber(): Type
 		return new ErrorType();
 	}
 
+	public function toBitwiseNotType(): Type
+	{
+		return new ErrorType();
+	}
+
 	public function toAbsoluteNumber(): Type
 	{
 		return new ErrorType();

src/Type/ClassNameToObjectTypeResult.php

@@ -0,0 +1,24 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Type;
+
+/**
+ * Result of projecting a "class-name-or-object" `Type` to its corresponding
+ * `ObjectType` for an `instanceof` / `is_a` check.
+ *
+ * `$uncertainty` is `true` when the projection lost information that prevents
+ * a definite yes/no decision later — e.g. a runtime class string was kept
+ * symbolically instead of being resolved to a concrete object type. Composite
+ * types OR-fold the flag across their members.
+ */
+final class ClassNameToObjectTypeResult
+{
+
+	public function __construct(
+		public readonly Type $type,
+		public readonly bool $uncertainty,
+	)
+	{
+	}
+
+}